1. Field of the Invention
The present invention relates to a component assembly in which plural components are assembled and an electronic apparatus a part of the housing of which is formed of the component assembly.
2. Description of the Related Art
There have been demands for electronic apparatus such as a personal computer and a cellular phone satisfying user friendliness and functionality, however, industrial design is also an important factor for selection for a user. Typically, electronic components are attached to a strong metallic housing frame to prevent the electronic components from being damaged by shock or the like. The housing frame is covered with a plastic cover to improve appearance.
At the time of repair, however, the cover is removed from the housing frame and then the cover is attached again to the housing frame. At this point, if a screw is forcibly fastened into a wrong screw hole, the cover may be damaged, appearance may be marred or an interstice may be formed between the cover and the housing frame, through which moisture or dust enter to cause a failure. In order to avoid such an inconvenience, in general, the cover is first tentatively fixed to the housing frame and then the cover is fixed to the housing frame with a screw at the time of attaching the cover to the housing frame. As methods of tentatively fixing the cover to the housing frame, there have been generally utilized a technique (refer to WO99/10860) in which the battery cover of a cellular phone is detachably attached to the housing of a main body and a technique (refer to Japanese Patent Application Publication No. 05-59682) in which the cover of a recording cartridge such as a video tape is opened or closed to engage a prong or a protrusion provided on the cover with a locking hole or a recess provided on the housing frame. Three conventional methods of fixing a cover are described below.
FIG. 1 is a schematic diagram describing a first method of fixing a cover to a housing frame.
In the cover fixing method in FIG. 1, a protrusion 511a provided on a cover 511 is fitted into the recess of the housing frame 512 to tentatively fix the cover to the housing frame 512 and then the cover 511 is fastened with a screw 515 from the other side thereof. In addition, resin components 513 and 514 made of the same resin as the cover 511 are fixed to the housing frame 512 by integral molding. The resin components 513 and 514 and the cover 511 conceal electronic components and the housing frame 512. The cover fixing method can easily attach the cover 511 to the housing frame 512 while avoiding an erroneous attachment, however, has a problem in that it takes cost and time to fix the resin components 513 and 514 to the housing frame 512 or to dismantle the resin components 513 and 514 at the time of a recycling work and the method is inflexible and thus cannot support variations of the cover 511.
FIG. 2 is a schematic diagram describing a second method of fixing a cover to a housing frame.
A cover 521 is provided with a hook 521a and a pawl 521b and the housing frame 522 is provided with locking holes at positions corresponding to the hook 521a and the pawl 521b respectively. As illustrated in Part (A) of FIG. 2, the hook 521a and the pawl 521b of the cover 521 are engaged with the locking holes of the housing frame 522 respectively to tentatively fix the cover 521 to the housing frame 522, thereafter, the cover 521 is fixed to the housing frame 522 with a screw. The cover fixing method illustrated in FIG. 2 can tentatively fix the cover 521 to the housing frame 522 while suppressing a cost. However, as illustrated in Part (B) of FIG. 2, the method has a problem in that the pawl 521b may be broken when the cover is removed from the housing frame 522 and therefore the cover 521 cannot be repetitively attached and detached.
FIG. 3 is a schematic diagram describing a third method of fixing a cover to a housing frame.
A cover 531 illustrated in FIG. 3 is provided with a hook 531a which is the same as the hook 521a in FIG. 2. A protrusion 531b is provided instead of the pawl 521b illustrated in FIG. 2. Furthermore, the cover 531 is provided with an auxiliary pawl 531c on a wall on the same side as the hook 531a. The use of the protrusion 531b makes engagement weaker than that of the pawl 521b illustrated in FIG. 2, thereby making it easier to remove the cover 521 from the housing frame 522. Even if the engagement by the protrusion 531b is released, the auxiliary pawl 531c hooks the housing frame 532 to surely tentatively fix the cover 531. As illustrated in Part (B) of FIG. 3, however, while the cover 531 is repetitively detached, the corners of the auxiliary pawl 531c are worn down to weaken the engagement of the auxiliary pawl 531c. As illustrated in Part (C) of FIG. 3, even when the hook 531a is not correctly engaged with the housing frame 532, the cover 531 can be forcibly but incorrectly fixed to the housing frame 532 with a screw by the elastic deformation of the cover 531.
As described above, the conventional cover fixing methods have problems in that they are costly, removing the cover only several times damages the cover and the cover can be fixed to the housing frame with a screw with the cover not correctly attached. In recent years, electronic apparatus are available in which a user may select a cover with his/her preferred color or appearance from among several kinds of covers. In future, it is assumed that the replacement of a cover will be common. As is clear from the above, the development of a cover and a housing frame is demanded which are easily and repetitively detachable.